An interpreter for heterogeneous prototypes of embedded software: Dissertation

A recent software development process model, the spiral model proposed by Boehm, suggests heterogeneous development where the high risk elements of the software are evaluated first, before entering detailed elaboration of low risk elements. The spiral model presents a major challenge to future software prototyping tools which, to be useful, must support prototyping at different phases of the development process and must support heterogeneous prototypes, i.e. prototypes that consist of parts that represent different abstraction levels of the software to be produced. We present an interpreter supporting heterogeneous prototypes of embedded systems based on executable specification techniques. The interpreter is based on defining a mapping from an extended data flow diagram notation, the transformation schema, to high level Petri nets, and a set of scheduling algorithms for execution of system models of different levels of abstraction. We have demonstrated the capability of the interpreter by constructing experimental prototyping tools supporting three of the abstraction levels proposed by the Ward & Mellor Structured Analysis for Real Time Systems (SA/RT) method. For an SA/RT logical model the interpreter supports graphical animation as a means of prototyping. For physical design models the interpreter supports both graphical animation and real time execution.